To set the keyframe interval for a Raspberry Pi camera using GStreamer, you can use the key-int-max parameter, which defines the maximum interval between keyframes (I-frames) for the video stream.

Here’s an example pipeline for setting the keyframe interval while using a Raspberry Pi camera with GStreamer:

Example GStreamer pipeline with keyframe interval set

gst-launch-1.0 rpicamsrc ! video/x-raw,framerate=30/1 ! videoconvert ! x264enc key-int-max=30 ! rtph264pay ! udpsink host=127.0.0.1 port=5000

Explanation

• rpicamsrc: This is the source element for the Raspberry Pi Camera.
• video/x-raw,framerate=30/1: Set the framerate of the captured video to 30 FPS (you can adjust this to your desired frame rate).
• videoconvert: Converts the video to a suitable format for encoding.
• x264enc: This encodes the raw video stream using the H.264 codec.
• key-int-max=30: This sets the maximum keyframe interval to 30 frames, meaning a keyframe (I-frame) will be inserted every 30 frames.
• rtph264pay: Payloads the H.264 stream for RTP transmission (you can adjust this part depending on your use case, like streaming via RTSP, file saving, etc.).
• udpsink host=127.0.0.1 port=5000: Sends the RTP stream over UDP to the specified host and port (this example sends it to the local machine).

Adjusting the Keyframe Interval

• You can increase or decrease the value of key-int-max depending on your needs. For example, setting it to key-int-max=60 will insert a keyframe every 60 frames.

Other Considerations

• When setting a high keyframe interval (e.g., key-int-max=60), video compression efficiency may be higher, but it may lead to more difficulty in seeking or recovering from errors in video streams.
• A smaller keyframe interval (e.g., key-int-max=15) will result in more frequent keyframes, making the video more resilient to packet loss, but may increase the bitrate.

Conclusion

Setting the keyframe interval on a Raspberry Pi Camera using GStreamer is essential for optimizing video streaming and encoding performance. 

By adjusting the key-int-max parameter, you can control the frequency of keyframes, balancing video quality and network efficiency. Whether you're streaming, recording, or encoding, this tweak ensures smoother playback and error resilience.